1. Field of the Invention
This invention relates generally to apparatus for tying concrete form panels together, and more specifically, to a tapered tie for use in such apparatus.
2. Description of the Prior Art
Various devices are known in the construction industry for holding concrete form panels together to adequately receive and support concrete poured inside them to form a wall or other structural unit. One example of such a device is shown in U.S. patent application Ser. No. 576,862, filed May 12, 1975 by James K. Strickland et al, now Pat. No. 4,044,986, and assigned to the assignee of the present application. One feature of the apparatus shown in this prior application is the use of a tapered tie to hold the concrete form panels together. Such ties are conventionally made from a plurality of steel rods threaded together or cast into a one-piece steel tie to have sufficient strength to hold the form panels together and to withstand the stresses imposed upon the ties.
A number of disadvantages are associated with ties fabricated from steel. When such ties are embedded inside the concrete column for the necessary length of time needed for the column to set, the ties sometimes rust or might have been rusty when first emplaced, thereby leaving rust spots on the completed concrete structure marring its appearance. Furthermore, steel ties are extremely heavy which increases their shipping weight and makes them difficult to handle. In addition, since such ties must often have a tapered shape, special casting equipment is needed to make the ties. If it were desired to vary the degree of the taper or otherwise change the shape of the steel tie, new and expensive casting equipment is required for each shape. Conventional steel ties are thus expensive to fabricate and, practically speaking, have a limited geometric capability.